Abstract:
Reporting its work in the Journal of the American Chemical Society, a team of investigators led by Moungi Bawendi, Ph.D., of the Massachusetts Institute of Technology, describes its efforts to create a new type of quantum dot that absorbs near-infrared light. This portion of the spectrum is not absorbed by water or biomolecules, and thus, can pass a significant distance through skin. The fruits of the groupís labors is a family of quantum dots that have a core of indium selenide surrounded by a shell of zinc sulfide. The core is further coated with dihydrolipoic acid connected to a short length of poly(ethylene glycol). The dihydrolipoic acid helps the quantum dots mix easily with water, while the poly(ethylene glycol) prevents proteins in blood and serum from sticking to the quantum dots.